[3] Individual research on the topic is often done by taking multiple samples along a transect from a city center and working outwards.
In ecosystem services, rural-urban gradients have shown Anthropocene effects affect their surroundings in multiple ways.
[10] This, combined with research that traffic corridors help to disperse non-native species,[11] make that non-native species also follow a rural-urban gradient, with the highest concentration in the cities and lower concentrations as you go outwards from the city.
Research on the common sparrow (Passer domesticus) has shown that populations along a rural-urban gradient can also genetically differentiate from one another over relatively small distances.
However, since the different populations are not isolated, it is unclear whether this is an evolutionary change or part of behavioral plasticity.